This invention is directed to a vertical speaker array which is associated with a vertical horn array. Each of the horns share a common vertical mouth and each of the speakers are connected to one of the horns to form common backloading and phasing of the speakers
In my prior U.S. Pat. No. 4,553,628, entitled Speaker System, I disclosed a phased array of speakers which can function as a line source for the generation of a wave form having improved directional frequency response with the sound concentrated in a flat pancake like sound field. In the speaker system of my prior patent, a vertical array of speakers are each equipped with an acoustical baffle device on the back side of the diaphragm of each of the speakers. An opening is located in this acoustical baffle device and a flexible tube is attached to the opening. The flexible tubes leading from each of the speakers are then fed to a common resonating chamber which in turn is connected to an acoustic horn. By connecting each of the vertically arrayed speakers to the common resonator chamber each of the speakers is backloaded to the same extent and driven in-phase with each other.
The positioning of the speakers in my device of U.S. Pat. No. 4,553,628 results in the improved directionality of the acoustic wave form emanating from the speaker device and the connection of the acoustical baffles of each of the speakers to a common resonating chamber results in common backloading and phase characteristics of the speakers.
Because the speaker system of my prior U.S. Pat. No. 4,553,628 utilizes a common resonator chamber which leads to an acoustic horn, it was difficult to effectively extend the line source sound wave emanating from this speaker system when placing two or more of these speaker systems in a stacked orientation or side by side. This speaker system, however has improved characteristics compared to simply a stacked array of speakers because it maintains an equal attenuation across a broad spectrum of frequencies at different orientations in a horizontal plane with respect to the axis of the speaker system. That is, when the listener is positioned off axis from the center axis of the speaker system at different orientations as, for instance, 30.degree., 60.degree. or 90.degree., little attenuation of the wave form is noticed compared to substantial distortion of the wave forms in a simple stacked speaker array.
While the directivity of a simple stacked array of speakers is inferior to that of the speaker system disclosed in my U.S. Pat. No. 4,553,628 it is, in fact, much better than that achievable with simple point source speakers because of improvements in maintaining the sound waves orientated essentially in a horizontal direction in vertical speaker array versus the overall spreading of the sound waves both horizontal and vertical in a point source speaker.